Environmentalists in favor of the bill say the lightweight material breaks down into beads that can be carried long distances. Polystyrene foam containers, they claim, account for 15% of California's litter. Lowenthal said the measure would help protect the environment, create green jobs and save taxpayers millions of dollars in cleanup costs. Nearly 50 cities in California already have similar bans in place.

Groups opposing the legislation, including the California Restaurant Association, say the foam is the best material for food packaging because it is inexpensive, lightweight and maintains food temperature.

Lowenthal plans to amend his bill in the Assembly to postpone the date for compliance with the ban from the original 2014 deadline to 2016 for restaurants and other food outlets, and 2017 for school districts. The Assembly is scheduled to hear the bill at the end of August; if it passes there, it will move to the governor's desk.